1992 300D OM603

Sometimes the electronic parts of the cluster stop working (fuel gauge/coolant temp/oil pressure), speedo still works though.

Idle drops or fluctuates a bit too.

Then it comes back like nothing happened.

I searched and a lot of people that had it say its a loose connection at the fuses. I removed and reinstalled all cluster related fuses (all copper), and it stopped for a while, but problem is starting to come back.

Any advice on what else to check on?